273 Rev. W. A. Leighton on the British Graphidese. 



the central parts, swollen, thickened and upraised into a narrow 

 spurious margin about the lirellse. Lirellce very numerous and 

 crowded, exceedingly long and very slender, straightish or wavy, 

 or curving and twisting in various degrees and ways, but all 

 maintaining more or less of a horizontal parallel direction rela- 

 tive to each other, more especially recognizable towards the 

 margins of the patch, simple or with a curved branch, either at 

 right angles from the middle or near one or both extremities, 

 which are also either one or both furcate, or crooked or simple ; 

 extremities obtuse or obtusely pointed or more or less acute, im- 

 mersed in and on a level with the spurious margin. Disk when 

 dry very narrowly rimseform, when wetted exceedingly narrow, 

 of nearly equal width throughout, with scarcely any discernible 

 pruina, encompassed by a slender wavy, curved and crisped, 

 elevated black proper margin. 



^. divaricata. Lirellse short and straight, divaricately branched. 

 Graphis serpentina, var. divaricata, Leight. Lich. Brit. Exsic. 21 ! (1851). 



On oak and ash. Sussex ! Mr. Borrer. Colin Glen, Belfast ! 

 Bangor, Co. Down ! Tullamore Park, Co. Down ! Knockdolian, 

 Ayrshire ! Rammerscales, Dumfriesshire ! Mr. W. Thompson. 

 Oxfordshire ! Baxter in herb. Dr. R. K. Greville. Tunbridge 

 Wells ! Mr. W. Thompson. Gloddaeth near Conway, Caernar- 

 vonshire ! 



Thallus thin, membranous, continuous, pale yellow or pale 

 olive, slightly shining or dull, generally smooth, sometimes with 

 tubercles and rugosities, scarcely if at all raised into spurious 

 margins about the lirellse. Li7-ellce numerous but not crowded, 

 small, short and straight, or only slightly curved, with a short, 

 simple, straightish or curved branch at right angles from the 

 middle, the extremities more or less acutely pointed, a little 

 raised above the thallus. Disk narrow and canaliculate when 

 dry, when wet expanded and more or less pruinose, surrounded 

 by a rather stout wavy proper margin. 



No, 87 in my copy of " ed. alt. immut.,^' Schser. Lich. Exsicc, 

 seems identical with this variety. No. 87 in Mr. Borrer^s copy 

 of the 1st ed. is referable to var. spathea. 



7]. radiata. Lirellse radiate. 



On young oak. Sussex ! Mr. Borrer. 



Thallus thin, subtartareous, irregularly rugose, pale yellow, 

 whitish, the spurious margins by reason of the crowded state 

 and peculiar form of the lirellse obliterated, only here and there 

 visible in a slight rugosity. LirellcB very much crowded, ar- 

 ranged in a radiate manner from a common centre, the radiations 



